This application claims benefit under 35 USC 371 of PCT/DE98/03648 filed Dec. 8, 1998.
The invention relates to a method for the manufacture of a food or a feed and to a product manufacturable by it.
The problem arises in the food and feed industry to simply and efficiently manufacture products, which comprise a plurality of densely superimposed and often very thin layers, between which are provided in each case or at least partially a thin air or liquid layer.
A classic example is puff paste, which is also an example for the use of traditional production processes for such products. Although the mechanical production of puff paste nowadays represents a considerable advance, the known methods are still relatively complicated and fault-prone.
Another field of use consists of products produced using meat emulsions. Meat emulsions have long been used in the food and feed industry, particularly in pet foods, to a considerable extent. A need exists for the use of a high proportion of meat raw materials, optionally combined with vegetable proteins, because these represent important nutrient carriers for protein, mineral substances, trace elements, fat and vitamins, are highly compatible and highly digestible, as well as at the same time very tasty and therefore represent an optimum basis for an adequate nutrient uptake.
The general problem in this connection is that non-pretreated meat or fish raw materials almost completely lose their original texture during the unavoidably necessary sterilization process used in the production of corresponding products. However, this is an essential factor for acceptance on the part of humans and animals.
EP-A-265 740 discloses a method for the manufacture of a meat emulsion product, in which a meat emulsion having a specific composition is rapidly heated to temperatures above 100xc2x0 C., preferably between 104 and 118xc2x0 C. At such a temperature the animal and vegetable proteins in the emulsion coagulate and denature at a very high speed. The hot emulsion is subsequently pumped into a process tube, where it remains under an overpressure until the proteins have completely coagulated. However, for reasons of nutritional physiology, the premature coagulation and denaturing of preteins in the emulsion has proved to be disadvantageous. In such manufacturing processes, more particularly the meat raw materials lose their texture and an attempt is made to compensate this, although only with a moderate level of success, in the known method by an energy and labour-consuming process stage of controlled evaporation of water present in the emulsion or additional injection of superheated steam for producing a layer-like structure.
German patent 39 33 528 discloses a process, in which a meat emulsion is forced through a gap between plates of a high speed emulsifier into a process tube and rapidly heated to 40 to 75xc2x0 C. The proteins contained in the starting materials are essentially of animal origin and have different coagulation behaviour characteristics with respect to the temperature and time duration. Although this method permits the production of products having an improved texture and better characteristics from the nutritional physiology standpoint, there are still considerable differences compared with naturally cut meat or fish portions, particularly with regards to the texture. In addition, the known method is relatively difficult to control and leads to not constantly good results.
The problem of the invention is to so improve known methods for the manufacture of foods or feeds, as described hereinbefore, that they lead to superior products and/or the control of the method is much less costly and more efficient.
According to the invention this problem is solved in the case of the method according to the preamble, in that at least one first material flow of a viscous mass, which hardens under corresponding, first method conditions, and at least one second material flow of a mass with a similar viscosity to the first material flow and which liquefies under corresponding, second method conditions, are so mixed together that the individual material flows are superimposed in layer-like manner and that subsequently, successively or simultaneously, the method conditions for solidifying the first material flow or liquefying the second material flow are implemented.
In a preferred embodiment of the invention the first material flow is a viscous emulsion.
According to another embodiment of the invention, the first or a further first material flow comprises a viscous dough based on flour.
According to the invention the second material flow is a viscous gel.
The invention also proposes that the second or a further second material flow consists of a viscous fat or a viscous, fat-containing substance.
According to an embodiment of the invention the method conditions necessary for solidification is constituted by a time sequence adequate for solidifying the first material flow or flows.
According to another embodiment the optionally additional method conditions necessary for solidifying the first material flow or flows is an application of heat. The heat can be applied in a subsequent sterilization stage.
According to the invention the first and second material flow or flows are used in a weight ratio of 50:50 to 95:5. A weight ratio of approximately 80:20 is particularly preferred.
In an especially preferred embodiment of the invention the first material flow or flows contain meat and/or fish materials or components thereof.
It is particularly preferable if the first material flow or flows additionally contain fibre-like or fibre-containing material.
In a preferred embodiment the first material flow or at least one of the first material flows contains alginate and at least one calcium salt in roughly equimolar quantities.
In a preferred embodiment of the invention the alginate used is sodium alginate and the calcium salt used is calcium sulphate.
In another embodiment of the invention, immediately prior to the mixing with the second material flow or flows, the corresponding material flow is prepared by mixing a mixture containing the calcium salt and an aqueous solution of the alginate.
The dough is of a type conventionally used in the baking industry, such as e.g. puff paste or dough.
In a preferred embodiment the invention proposes that the viscous gel contains a gel-forming substance from the group comprising carboxymethyl cellulose, guar gum and other hydrocolloids.
According to the invention the viscous gel comprises carboxymethyl cellulose.
The invention proposes that the viscous gel contains a calcium salt.
In particularly preferred manner calcium lactate is used as the calcium salt.
According to another embodiment of the invention the fat or fat-containing substance used is a substance normally employed in the baking industry, such as e.g. margarine, butter, butter fat or pastry fat.
In another embodiment of the invention the mass resulting from the super-imposed single material flows is cut into suitable sizes following solidification.
According to a preferred embodiment of the invention at least one first material flow and at least one second material flow are supplied separately from one another to a distributing zone running circumferentially about a longitudinal axis, the distributing zones being separated from one another, each material flow is passed into a delivery zone following onto the distributing zone, the delivery zones being separate from one another and distributed in juxtaposed manner around the longitudinal axis and connected to the in each case associated distributing zone, the material flows passing out of the delivery zones with in each case predetermined cross-sectional shape and surface are passed longitudinally within a given overall cross-section, and in their arrangement as a whole the delivery zones are rotated about the longitudinal axis, the individual material flows being spirally superimposed in layer-like manner.
The invention proposes that the distributing zones are circular or annular in cross-section.
Appropriately at least one delivery zone is slot-like in cross-section.
Appropriately at least one delivery zone is circular sector-shaped in cross-section.
In another embodiment of the invention the at least one delivery zone is split up into a row of radially succeeding partial zones.
According to a particularly preferred embodiment of the invention two material flows and two delivery zones are used.
It is also possible for the discharged material to be guided in a cross-section changing in defined manner in the longitudinal direction.
The invention also relates to a feed or food manufacturable according to the method of the invention, provided that the first material flow comprises a viscous emulsion, preferably a meat emulsion.
The fundamental idea of the invention is based on the fact that it is surprisingly efficiently and inexpensively possible to manufacture the desired products in that at least two viscous masses, which behave differently under corresponding method conditions, namely firstly a solidified mass and secondly a liquefied mass, are mixed with a suitable mixing process permitting the superimposing of optionally thin layers.
Following onto the mixing process initially firstly there is a passage through the solidification mechanism (e.g. chemical reaction of alginate with calcium salts, heat application, etc.), in order to prestructure the product. This is followed by process conditions under which the second viscous mass is liquefied, so that the latter can optionally at least partly be discharged.
In the case of the manufacture of a lumpy feed based on a meat emulsion, the cutting into pieces can take place before, during or after the solidification stage. For such a product a preferred solidification stage is the chemical reaction of alginate with calcium salts, which has been fundamentally been well known for decades from the food and feed technology field.
The lumpy products, i.e. in alternating manner a solidified meat emulsion layer and a viscous gel layer, can then be packed, e.g. canned in this form and accompanied by the addition of a corresponding gravy. During the subsequent sterilization stage, the viscous gel is liquefied and largely passes out into the surrounding medium, in order to leave behind the corresponding, desired, layer-like material, which is very similar to natural pieces of meat. In this case the method is particularly economic, because the liquefaction stage is performed automatically during a method stage which must in all cases be carried out, namely sterilization.
In the case of the manufacture of a dough or paste product, such as e.g. puff paste, following mixing and discharging from the mixing apparatus and optionally following portioning, initially the aforementioned solidification stage is passed through, i.e. the baking stage. In this case the liquefaction stage of the intermediate layer of fat or fat-containing substance takes place simultaneously with the solidification stage, because for one mass, namely the paste, the heat application brings about solidification, whereas for the other mass, namely the fat or fat-containing substance, it brings about liquefaction. The liquefying fat can firstly pass out laterally and be collected, but is largely absorbed by or remains between the dough or paste layers.
Obviously the method according to the invention is not restricted to the two fields of application described in detail, but can instead be used where corresponding, layer-like products are to be produced, provided that it is possible to fulfil two essential fundamental conditions, firstly the setting of roughly identical viscosity for the mixing stage, because it would otherwise be difficult to achieve a corresponding layer structure of the materials, and secondly the composition of the material flows must be so selectable that one material flow solidifies under corresponding method conditions and the other material flow liquefies under corresponding method conditions, in which said method conditions need not necessarily be identical, such as e.g. heat application, but it must at least be ensured that the method conditions leading to the solidification of one material flow do not so modify the other material flow that a subsequent liquefaction would be prevented.